Laserfiche WebLink
A corrosion suite (pH, resistivity, and chloride content) was also performed on a sample obtained from <br />the geotechnical boring to estimate the corrosion potential of onsite soils. The resistivity tests resulted <br />in a minimum resistivity of 2,100 ohm -centimeters, a pH of 7.76, and chloride content of 130 ppm. <br />Test results are provided in Appendix C. These results/assumptions should be confirmed at the <br />completion of site grading. <br />Results of the previous laboratory testing (by ACG) performed during the previous site investigation <br />indicated expansion index ranging from 69 to 94 (Medium to High Expansion potentials), soluble <br />sulfate content of non -detectible to 0.017%, Minimum Resistivities ranging from 680 to 1,700 ohm - <br />cm, Chloride content of 15 to 65 ppm, and pH ranging from 7.94 to 8.04. Previous testing also <br />included maximum density and optimum moisture tests, consolidation, and grain size distribution. <br />The previous test results are included in Appendix C of this report. <br />2.11 Percolation Testing <br />Preliminary percolation testing was performed as a part of the previous site investigations (by ACG), <br />a discussion and the results of the preliminary testing (by ACG, 2021) is provided herein. it is our <br />understanding that the project may utilize infiltration systems for storm water disposal. Details of the <br />system are not known at this time. <br />Shallow infiltration testing was performed in three (3) five -foot -deep borings (P-1 through P-3) <br />located across the site. The location of the percolation tests is shown on the attached Figure 2. The <br />following discussion and information are from the referenced report. The testing was performed in <br />general accordance with the County of Orange Technical Guidance Document. The three test wells <br />were presoaked at least 24 hours prior to testing. During testing, the water level readings were <br />recorded every 30 minutes until the readings stabilized. The data was then adjusted to provide an <br />infiltration rate utilizing the Porchet Method. The resulting infiltration rates are presented in Table 2. <br />The results do not include a factor of safety. <br />Table 2 <br />Summary of Infiltration Testinz (No Factor of Safety) <br />Test Designation <br />P-1 <br />P-2 <br />P-3 <br />Approximate Depth of Test <br />5 ft <br />5 ft <br />5 ft <br />Time Interval <br />30 minutes <br />30 minutes <br />30 minutes <br />Radius of Test Hole <br />4 inches <br />4 inches <br />4 inches <br />Tested Infiltration Rate <br />4.1 in/hr <br />5.0 in/hr <br />6.2 in/hr <br />Project i y 6unci1 18 — 825 1 316, 2021 <br />